Segment Routing is a network technology that provides enhanced packet forwarding behaviour while minimizing the need for maintaining awareness of mass volumes of network states.
It is commonly used for application-enabled routing in software defined networks as it has the ability to provide strict network performance guarantees, efficient use of network resources and very high scalability for application-based transactions.
Segment routing technology has been defined for Multi Protocol Label Switching (MPLS) and Internet Protocol version 6 (IPv6) data planes.
In contrast, at present, non-packet transport networks such as optical networks are typically controlled based on fully distributed Generalized MPLS (GMPLS) control panes or a fully centralized control plane, for example an Open Flow based Software Defined Networking (SDN) solution.
However, fully centralized solutions are highly dependent on the availability and connectivity of an SDN controller and often have low performance in terms of scalability and resiliency.
Furthermore, fully distributed GMPLS control planes rely on signalling protocols, which implies a high effort in terms of the configuration maintenance and management complexity of the control plane. Also, as this is as stateful approach a periodic update is required.